locate program relies on a database which is periodically
built by the updatedb program. That hasn't happened in a long
time. To fix this problem, run updatedb manually. This can
often happen on systems that are generally not left on, so the periodic
“cron” task which normally does this doesn't get a chance to run.
updatedb. If that works, but
locate still produces this error, run locate --version
and updatedb --version. These should produce the same output.
If not, you are using a mixed toolset; check your $PATH
environment variable and your shell aliases (if you have any). If
both programs claim to be GNU versions, this is a bug; all versions of
these programs should interoperate without problem. Ask for help on
bug-findutils@gnu.org.